A knowledge graph or an ontology includes types, properties, and interrelationships between entities that exist in a domain of discourse. A knowledge graph compartmentalizes variables needed for some set of computations, and establishes relationships between the variables. The fields of artificial intelligence, systems engineering, software engineering, biomedical informatics, library science, enterprise bookmarking, and/the likes create knowledge graphs or ontologies to limit complexity and organize information. A knowledge density of a knowledge graph is an average number of attributes and binary relations issued from a given entity, and is measured in facts per entity.